2. The microorganism must be isolated from the victim in pure culture (i.e., in a culture containing only that single kind of organism).

3.When the microorganism from the pure culture is injected into a susceptible host organism, it must produce the disease in the host.

4. The microorganism must be isolated from the experimentally infected host and grown in pure culture for comprison with the original culture.

Similarly,
if it is a parasite, then they will be present in all cases.

same microorganism and same vector.
as the mosuito to malaria etc

Am I rambling?
Dont feel well. I am tired of feeling sick and tired!
I better sign off
lol

ps: I think this thread is fizzing out.
Respectfuly yours,
Linn

"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".

"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".

It is known that a key protein in the immune system, C3, bonds with and
interacts with up to 40 other proteins and receptors in the blood. But until
now it has not been understood what the significance of these bonds might
be. In the latest issue of the scientific journal Nature a Swedish-Dutch
research team has laid bare the crystal structure of the protein, which may
lead to tailor-made treatments for autoimmune diseases.

Scientists at Uppsala University, in collaboration with the universities of
Utrecht and Leiden in the Netherlands and Kalmar in Sweden have managed to
describe the crystal structure of one of the key proteins in the natural
immune system, complement factor C3. This protein was isolated and
characterized for the first time here at Uppsala University more than 40
years ago. A large number of studies have shown since then that the protein
bonds with and interacts with 30-40 other proteins and receptors in the
blood and on white corpuscles. But despite repeated attempts, it had not
been possible to determine its crystal structure, and this has hampered our
understanding of these bonds.

- The protein is of great importance to the body's defense against
micro-organisms and is one of the main factors in the inflammatory process
in many autoimmune disorders,says Bo Nilsson, Department of Clinical
Immunology, who directs the research team.

The three dimensional structure now shows that the protein developed from a
proto-protein about 800 million years ago and that this protein has since
given rise to several other defense proteins in organisms from insects to
mammals. The structure also shows that the protein undergoes a drastic
metamorphosis after it has become activated, which will explain how the
interplay with other proteins is regulated. The new findings may lead to
tailor-made drugs to regulate the destructive inflammatory processes that
are associated with autoimmune diseases like arthritic rheumatism, SLE,
vascular inflammations, hemolytic anemias, kidney inflammations, and blood
poisoning.

For some time, researchers have known that the C3 protein of the complement
system plays a major role in inflammation and tissue damage, which are
hallmarks of lupus. Research has also shown that people with an inherited
deficiency in the C1 or C4 proteins of the complement system, which can
activate C3 and trigger inflammation in a chain reaction, have a high risk
of developing lupus. These latter findings led to the hypothesis that C1 and
C4 "have some protective role in keeping us from developing lupus," says
Michael C. Carroll, PhD, of Harvard Medical School.
To learn more about the role of complement system proteins in the
development of lupus, Dr. Carroll and his colleagues are using a mouse model
of lupus in which they can eliminate individual proteins through genetic
engineering. "It turns out that in mice it's the same story" as in people,
Dr. Carroll says. In the February 1 issue of the Journal of Immunology, he
and his co-workers report that mice that are normally prone to a mild form
of lupus develop a more severe form of the disease when they are deficient
in C4, and that eliminating the C3 protein does not protect the C4-deficient
mice from developing lupus. These studies show that C4, and not C3, plays an
important role in the initial development of lupus.
In a similar research project supported by ALR, David Pisetsky, MD, PhD, of
Duke University Medical Center is also using mice deficient in components of
the complement system to better understand the role of complement deficiency
in lupus development, and to determine whether complement proteins could be
used as a treatment for
In a previous work, it was demonstrated that the C3 gene is encoded by
bacteriophages C and D of C.botulinum by using DNA-DNA hybridizations with
oligonucleotides deduced from the C3 protein N-terminal sequence. The C3
coding gene was cloned and sequenced, but its upstream DNA region could not
be studied because of its instability in Escherichia coli. In this work, the
upstream DNA region of the C3 was directly amplified by the polymerase chain
reaction and sequenced. The C3 gene encodes a polypeptide of 251 amino acids
(27 823 Da) consisting of a 40-amino-acid signal peptide and a mature
protein of 211 amino acids (23 546 Da). The C3 mature protein was expressed
in E.coli under the control of the trc promoter. The recombinant polypeptide
obtained was recognized by C3 antibodies and ADP-ribosylated the Rho
protein. The C3 gene nucleotide sequence is identical on C and D phage DNAs.
At the amino acid sequence level, no similarity was found among C3, other
ADP-ribosylating toxins, or tetanus or botulinal A, C1,

$1.2 Million Grant for Further Development of Compstatin, A Drug to Halt
an Overzealous Immune System (Philadelphia, PA) -- In some ways, the body's
first line of defense can also be its worst enemy. The complement system is
a series of biochemical reactions that activate in response to foreign
molecules and is an important part of the immune system. Unfortunately, when
it is activated at the wrong time, complement is also responsible for organ
transplant rejection and a long list of diseases. Researchers at the
University of Pennsylvania Medical Center have found a way to control
complement with Compstatin, a small molecule that blocks the reactions
involved in a complement response. The National Institute for General
Medical Sciences (NIGMS) has awarded John D. Lambris, PhD, a professor in
the Department of Pathology & Laboratory Medicine, a $1.2 million grant to
continue the development of Compstatin into an effective drug. "Among the
compounds we have studied, I believe Compstatin holds real promise," said
Lambris. "Until Compstatin, most complement inhibitors were either only
marginally effective or actually toxic to humans." Part of the reason it has
been so difficult to control complement is because of the complex nature of
the human immune system. Complement proteins serve as a passive alarm
system, watching for pathogens that may enter the blood system. When a
complement protein finds something it does not recognize, it attaches itself
to the invader, summoning the full wrath of the immune system, which
attempts to destroy the invader. Complement is not a simple sequence of
reactions either, but a series of interlocking cascades, or chain reactions,
of biochemical events involving at least 30 proteins. "Fortunately, there is
a point where all the protein cascades intersect," said Lambris. "We figured
that if we can stop the cascade at this point, we can halt the reaction
regardless of what pathway started it." Lambris and his colleagues focused
on one particular complement protein, an enormous molecule called C3. They
created billions of protein fragments and searched for ones that might bind
to the C3 protein and inactivate it. Amazingly, they found a ring-shaped
protein, made up of 11 amino acids, which, despite its relatively small
size, inactivated C3 entirely. Lambris named the molecule Compstatin. "Since
C3 was so large, we assumed that we would find many different fragments that
would bind to C3, and from them we would learn more about the important
functional parts of the molecule," said Lambris. "Instead, out of all the
possibilities we find the one fragment that attaches directly to C3 and
disables it." Compstatin owes its effectiveness -- and potential use as a
therapeutic -- to its small size. Compstatin's ring structure makes it
resistant to proteases, enzymes that destroy proteins, so it is less likely
to be broken down before it meets its target. Smaller molecules like
Compstatin are also more readily adaptable to use as an oral medication.
Lambris and his colleagues have already demonstrated Compstatin's abilities
in the laboratory, and the NIGMS grant makes further exploration possible.
"Compstatin has great potential as a complement inhibitor," said Mark
Tykocinski, MD, Chair of Penn's Department of Pathology and Laboratory
Medicine. "Developing complement inhibitors with therapeutic potential has
been a long-standing goal of medical science, and such agents could
contribute significantly to the treatment of an array of human diseases."
Although the complement proteins are part of the immune system, they do not
always limit themselves to potentially disease-causing invaders-- complement
does not discriminate between bacteria and transplanted organs or even
implanted surgical devices. Complement can also attack healthy tissue, and a
variety of diseases are associated with complement gone awry, such as
multiple sclerosis and hemolytic anemia. In addition, complement is thought
to play a role in the destruction of cells during strokes, heart attacks,
and burn injuries. The University of Pennsylvania Health System is
distinguished not only by its historical significance --first hospital
(1751), first medical school (1765), first university teaching hospital
(1874), first fully integrated academic health system (1993) --but by its
position as a major player on the world stage of medicine in the 21st
century. Penn ranks second among all American medical schools that receive
funds from the National Institutes of Health, perhaps the single most
important barometer of research strength. Almanac, Vol. 47, No. 26, March
20, 2001 |

This is a blood test that measures one component of the complement cascade. Complement is a group of blood proteins that cause immune responses and inflammation. The complement cascade is a series of reactions that take place in the blood. There are 9 major complement components, labeled C1 through C9. This test measures C3.

How the test is performed Return to top

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

How to prepare for the test Return to top

There are no special preparations.

For infants and children:

The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics:

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed Return to top

Complement activity (CH50, CH100, terminal complement component, or individual complement proteins) is measured to determine if complement is involved in the development of a number of diseases.

Complement activity is also measured to monitor how severe a disease is or to determine if treatment is working. For example, patients with active lupus erythematosus may have low levels of C3 and C4, and these component levels may be watched as an indicator of disease activity.

Patients with gram negative septicemia and shock often have very low or no C3, and C3 is often also low in fungal infections and some parasitic infections such as malaria.

excessive bleeding
fainting or feeling light-headed
hematoma (blood accumulating under the skin)
infection (a slight risk any time the skin is broken)
multiple punctures to locate veins
Special considerations Return to top

The complement cascade can be started in several ways, especially by antigen-antibody complexes. The end-product of the cascade is the "membrane attack unit" (also called terminal complement component), which creates holes in the membranes of attacking bacteria, thereby killing them.

CH50 and CH100 are tests for the activity of the complement system. There are also a number of side products of the complement cascade that attract white blood cells and increase the efficiency of certain types of white blood cells to engulf and destroy bacteria.

Some bacteria don't need specific antibodies to be present for the complement system to be activated. C3, one of the major components of the complement cascade, attaches to and kills these bacteria directly.

Typically, other tests that are more specific for the suspected disease are performed first.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (http://www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (http://www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (http://www.hon.ch).

The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Adam makes no representation or warranty regarding the accuracy, reliability, completeness, currentness, or timeliness of the content, text or graphics. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2005, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Part of the both the innate and the humoral immune responses, the complement system is a group of secreted proteins that have been found to serve a number of functions besides fighting infection. The best-known product of the complement cascade is the membrane attack complex (MAC), proteins that bind to and kill microbes by forming channels in their cell walls. (Defects in the final segment of the complement cascade often lead to infections from Neisseria species of bacteria.) Other complement components include C3, which is instrumental in binding antigen-antibody complexes. (Defects in this complement component lead to a lupus-like syndrome and glomerular renal disease.) Two C3 cleavage products also play instrumental roles: C3b binds to antibody-coated microbes and greatly enhances phagocytosis by macrophages; C3d binds to B cells and markedly enhances antibody production.

Aiming to identify a peptide that binds to C3b (larger fragment of C3 complement protein) and could possibly influence the interactions of C3b with other complement proteins, a 27 residue peptide was identified by screening a phage-displayed random peptide library against C3b. This peptide, in fact, binds to C3, C3b, and C3c but not C3d. A synthetic peptide with the sequence of the phage-displayed peptide, reversibly inhibited complement activation in both the classical and the alternative pathways. Further experiments have shown that a patch of 13 residues within this 27-mer peptide is responsible for the C3 inhibition. The sequence of this 13 residue peptide is:Ile1-[Cys2-Val3-Val4-Gln5-Asp6-Trp7-Gly8-His9-His10-Arg11-Cys12]-Thr13-NH2 with a disulfide bond between Cys2-Cys12. This was later named as Compstatin. Further truncation yielded inactive peptide.

3D structure of Compstatin

The solution structure of compstatin has been determined by using 2D NMR techniques. Applying a hybrid distance geometry- restrained simulated annealing methodology and using distance, dihedral angles, and 3J(NH-alphaH) coupling constants, a family of 21 structures were generated. An average minimum and a global optimization structures make the family a total of 23 structures all of which consists of a type I beta turn comprising the segment Gln5-Asp6-Trp7-Gly8

Compstatin Analogs and Inhibitory Activity

To identify the essential residues of compstatin in its capacity of inhibiting C3, a series of compstatin analogs have been designed. At the first attempt, 11-residue peptide (excluding two terminal residues Ile1 and Thr13 outside the ring) was synthesized and subsequently 9 Ala mutants were generated replacing every residue (between Cys2 and Cys12) by Ala at a time. Replacement of Val4, His9, His10, and Arg11 resulted in minimal change in the functional activity. Replacement of Val3, Gln5, Asp6, and Trp7 reduced the activity by 6-36 folds. Replacement of Gly8 dramatically reduced the activity by more than 100 fold. This means that the calculated type I beta turn is important in preserving the conformational stability of compstatin and probably plays a significant role in its inhibitory activity. A large number of compstatin analogs have been designed thereafter and their C3 inhibition activities are shown below:

(a) Asterisks denote oxidized cysteines.
(b) Complement activities were determined by measuring alternative pathway-mediated lysis of erythrocytes. (c) Peptide II was reduced with DTT and alkylated using iodoacetamide. (d) Maximum concentration of peptide that could be used in the assay due to solubility limitations. (e) Cleaved between Arg and Cys.

It is clear that compstatin activity could be affected by several structural features. The rational design of several analogs potentially increases the inhibition activity and some other cases they lose activity. Moreover, a particular analog could have different activity in different species. For example, the following table shows complement inhibitory activities of compstatin and its analogs in humans, mice, and rats.

Although the presence of type I beta turn has been shown to be very important for its inhibitory activity, compstatin might undergo structural reorientation upon binding with complement proteins. This kind of conformational changes upon binding has been observed in other cases. We have performed 1 ns MD simulation of an ensemble of 23 structures of compstatin using Generalized Born implicit solvation and found that about 40% structures retained their original type I beta turn while four new families of secondary structures appear. This contains even some alpha-helix and 3-10-helix conformations. This study has aided to gain insight into the conformational space sampled by compstatin and have provided a measure of conformational interconversion. The calculated conformers will be useful as structural and possibly dynamic templates for optimization in the design of compstatin using structure-activity relations (SAR) or dynamic-activity relations (DAR) which can result in higher inhibitory activity. We beleive that it is necessary to incorporate the presence of more than one conformers into our thinking, within our rational or compbinatorial optimization, for compstatin and for peptide-drug design in general. In that sense, NMR data of ensemble of structures may be more suitable for MD simulations of peptides, rather than single crystallographic structure.

$1.2 Million Grant for Further Development of Compstatin, A Drug to Halt an Overzealous Immune System
(Philadelphia, PA) -- In some ways, the body's first line of defense can also be its worst enemy. The complement system is a series of biochemical reactions that activate in response to foreign molecules and is an important part of the immune system. Unfortunately, when it is activated at the wrong time, complement is also responsible for organ transplant rejection and a long list of diseases.

Researchers at the University of Pennsylvania Medical Center have found a way to control complement with Compstatin, a small molecule that blocks the reactions involved in a complement response. The National Institute for General Medical Sciences (NIGMS) has awarded John D. Lambris, PhD, a professor in the Department of Pathology & Laboratory Medicine, a $1.2 million grant to continue the development of Compstatin into an effective drug.

"Among the compounds we have studied, I believe Compstatin holds real promise," said Lambris. "Until Compstatin, most complement inhibitors were either only marginally effective or actually toxic to humans." Part of the reason it has been so difficult to control complement is because of the complex nature of the human immune system. Complement proteins serve as a passive alarm system, watching for pathogens that may enter the blood system. When a complement protein finds something it does not recognize, it attaches itself to the invader, summoning the full wrath of the immune system, which attempts to destroy the invader. Complement is not a simple sequence of reactions either, but a series of interlocking cascades, or chain reactions, of biochemical events involving at least 30 proteins.

"Fortunately, there is a point where all the protein cascades intersect," said Lambris. "We figured that if we can stop the cascade at this point, we can halt the reaction regardless of what pathway started it."

Lambris and his colleagues focused on one particular complement protein, an enormous molecule called C3. They created billions of protein fragments and searched for ones that might bind to the C3 protein and inactivate it. Amazingly, they found a ring-shaped protein, made up of 11 amino acids, which, despite its relatively small size, inactivated C3 entirely. Lambris named the molecule Compstatin.

"Since C3 was so large, we assumed that we would find many different fragments that would bind to C3, and from them we would learn more about the important functional parts of the molecule," said Lambris. "Instead, out of all the possibilities we find the one fragment that attaches directly to C3 and disables it."

Compstatin owes its effectiveness -- and potential use as a therapeutic -- to its small size. Compstatin's ring structure makes it resistant to proteases, enzymes that destroy proteins, so it is less likely to be broken down before it meets its target. Smaller molecules like Compstatin are also more readily adaptable to use as an oral medication.

Lambris and his colleagues have already demonstrated Compstatin's abilities in the laboratory, and the NIGMS grant makes further exploration possible.

"Compstatin has great potential as a complement inhibitor," said Mark Tykocinski, MD, Chair of Penn's Department of Pathology and Laboratory Medicine. "Developing complement inhibitors with therapeutic potential has been a long-standing goal of medical science, and such agents could contribute significantly to the treatment of an array of human diseases." Although the complement proteins are part of the immune system, they do not always limit themselves to potentially disease-causing invaders-- complement does not discriminate between bacteria and transplanted organs or even implanted surgical devices. Complement can also attack healthy tissue, and a variety of diseases are associated with complement gone awry, such as multiple sclerosis and hemolytic anemia. In addition, complement is thought to play a role in the destruction of cells during strokes, heart attacks, and burn injuries.

The University of Pennsylvania Health System is distinguished not only by its historical significance --first hospital (1751), first medical school (1765), first university teaching hospital (1874), first fully integrated academic health system (1993) --but by its position as a major player on the world stage of medicine in the 21st century. Penn ranks second among all American medical schools that receive funds from the National Institutes of Health, perhaps the single most important barometer of research strength.

Quorum sensing is bacterial load bound ( momentum bound)
= based on release of chemical signal
More than one signal is present.
Step, step, step

Indeed lysis(free flow of DNA) is related to fission.

All is about cloning

or the other meaning:

C3 represents class 3 or level 3 (human and or contagious pathogen)
This type research is only done in a highly protected environment.
check international protocol for C3 laboratory
All other association is fine embellishment.

***

Takes a bit to shift gears. I'll have to think of my 'game name'.

As UK guy stated- good work Randy.

Thing is- this test for C 3- what will that ultimately tell us? The list of
diseases that it is used for- Hepatitis- Lupus, etc.- how does that relate?

"How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in life you will have been all of these".